Two-Step Wireless Random Access Using Preamble-Data Mapping

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Solution Overview

Problem

Existing wireless communication systems face challenges in reducing random access delay, signaling overhead, and device power consumption, particularly in scenarios like ultra-reliable low latency communication and unlicensed spectrum, where traditional four-step contention-based random access procedures are inefficient.

Innovation Solution

A two-step contention-based random access procedure is introduced, with a method for determining transmission message resources and mapping between preamble and data portions, including various structural designs and multiplexing methods to reduce resource conflicts and optimize latency and overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If traditional four-step contention-based random access procedure is used, then compatibility with existing systems is maintained, but random access delay is increased

Engineering Contradiction:
Improverandom access delayVSAvoidaccess procedure steps
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent combines the preamble transmission and data transmission into a single message (Message A), eliminating the need for separate Message 1 and Message 3 transmissions. This merging of functions reduces the access procedure from four steps to two steps, directly reducing random access delay while maintaining system compatibility through the two-step structure.

Inventive Principle:
Principle #5Merging (Combining)

2Loss of information

If traditional four-step random access procedure is used, then thorough communication is achieved, but signaling overhead is increased

Engineering Contradiction:
Improvesignaling overheadVSAvoidcommunication efficiency
Core Design Contradiction:
Loss of informationVSProductivity

Solution Approach 1:

The patent merges multiple signaling functions into Message A, which contains both the preamble (for random access request) and the data portion (for uplink data or control information). This consolidation eliminates redundant signaling messages, reducing overall signaling overhead while improving communication efficiency through the streamlined two-step procedure.

Inventive Principle:
Principle #5Merging (Combining)

3Use of energy by moving object

If traditional four-step random access procedure is used, then complete access handshake is achieved, but device power consumption is increased

Engineering Contradiction:
Improvedevice power consumptionVSAvoidaccess procedure completeness
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent combines the random access request and data transmission into a single Message A transmission, allowing devices to complete the access handshake in fewer steps. This reduces the number of times the device needs to transmit and receive signals, thereby reducing power consumption while maintaining access procedure completeness through the integrated message structure that includes both preamble and data portions.

Inventive Principle:
Principle #5Merging (Combining)

4Device complexity

If preamble and data portions are transmitted separately, then resource allocation is simplified, but resource conflicts increase

Engineering Contradiction:
Improveresource allocationVSAvoidresource conflicts
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent combines preamble and data portions into a single Message A that is transmitted in one go, eliminating the need for separate resource allocations for Message 1 and Message 3. This unified transmission approach reduces resource conflicts because the resources are allocated once for the entire message rather than separately for each component, simplifying resource management while reducing conflicts.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3858017B1Random access in wireless communication
Publication Date: 2025.08.27 ZTE CORP
  • EP3858017B1 patent drawingFigure 1A~1B
  • EP3858017B1 patent drawingFigure 2~5
  • EP3858017B1 patent drawingFigure 6~7A

AI summary

A wireless communication technique includes generating, by a wireless terminal, a transmission message that includes a preamble portion and a data portion. In this technique, transmission resources for the data portion are related to transmission resources for the preamble portion using a relationship rule. The wireless terminal transmits the transmission message to a network-side device during a random access procedure.